3D84 3D88 4D84 4D88 Used Oil Pumps PC35 PC40 PC55 129006-42002
Specification
| Engine type: Diesel | Gear number: 29 |
| Category: Spare parts | Cylinders Number: 3 cylinders / 4 cylinders |
| Quality: High performance | Test staus: Normal |
| Car model: Direct Injection | Application: Excavator engine |
Description
Oil pickup pipe
The oil pump sucks oil up from the sump through a pipe - called a
pickup pipe. The pipe’s nozzle sits below the surface of the oil,
and it is covered by a guaze filter which prevents large particles
from being sucked up into the pump.
If this filter screen was to be completely blocked, then the engine
would not pick up any oil and the engine would at great risk of
being destroyed. Therefore the pickup pipe may have bypass valve in
case the screen is blocked. In this situation it’s better that the
engine continues to receive oil and we take the chance of damage to
the oil pump: an oil pump is considerably cheaper than an engine
rebuild.
Oil pumps
Most oil pumps are driven directly by the crankshaft. The pump
illustrated here sits over the nose of the crankshaft where its
internal gear is driven directly.
All oil pumps are called positive displacement pumps - the amount
of oil that leaves is the same as that enters. In other words, the
pump moves oil from one side, to the other. This can be contrasted
with a coolant pump, for example, which tries to move water but
will not do so if the pressure is too great on one side.
As engine RPM increases, the pump turns faster and more oil is
pumped. This is convenient because at higher engine speeds
lubcrication and cooling requires a greater flow of oil.
Working Principle
The oil pump is inevitable in an engine for lubrication as engines
need to be properly lubricated when it’s running. The oil pump is
usually a gear-driven from the crankshaft which start pumping oil
immediately the engine is running. In some oil-free engines like a
two-stroke, oil injectors are not used.
From a strainer, oil passes into the oil pump and then flows
through the heat exchanger, where it’s cooled. The cooled oil then
flows through the galleries to the moving parts of the engine
before returning to the sump. If an engine is designed with an
injector, a small portion of oil is diverted to it.
